Embedded hoist human-machine interface

ABSTRACT

A cable drum receives a length of working cable that is wound in and out from the drum in response to powered rotation of the drum with an uppermost layer of working cable on the drum forming a working surface. A torque sensor in communication with the cable drum measures a torque applied to the cable drum due to tension on the working cable from a load. A drum height gauge is provided for measuring a height of the working surface of the cable on the cable drum. A processor receives the torque value from the torque sensor and the height of the working surface from the drum height gauge and computes a force applied to the length of working cable due to the load based on the torque and height of the working surface. The work performed by the cable may be calculated to assist in determining cable health.

CROSS-REFERENCE TO RELATED CASES

This application is a continuation of U.S. patent application Ser. No.14/733,529 entitled EMBEDDED HOIST HUMAN-MACHINE INTERFACE filed on Jun.8, 2015 which claims the benefit of U.S. provisional patent applicationSer. No. 62/009,030 entitled EMBEDDED HOIST HUMAN-MACHINE INTERFACE,filed on Jun. 6, 2014 and U.S. provisional patent application Ser. No.62/031,710 entitled EMBEDDED HOIST HUMAN-MACHINE INTERFACE, filed onJul. 31, 2014, the contents of which are hereby incorporated byreference.

FIELD OF THE INVENTION

The present disclosure relates to winches and hoists in general and,more specifically, to a system for determining force applied to aworking cable during lifting or pulling.

BACKGROUND OF THE INVENTION

Modern cranes are ubiquitous to the construction and manufacturingindustries. In the past, cranes relied on operator experience and chartsin order to determine safe operating limits including boom angles, loadcapacity, and other operating parameters. Now, computers aid operatorsin quickly determining whether a given load or lift is safe undercurrent conditions.

In addition to knowing what tasks are safe to undertake, it is alsoimportant to know the current load or work being performed by the cranein order to ensure that the crane is operating under acceptable and safeparameters. Currently, in order to know the load placed on a crane,sensors may be placed within a hydraulic ram or piston that moves andstabilizes the boom in the vertical direction. However, this requiresplacement and wiring (or other communication means) between the boom andother measuring devices and computers that are normally locatedelsewhere on the crane. For example, cranes are often already outfittedwith devices such as load moment indicators (LMI) and drum rotationindicators (DRI).

Some components of cranes and associated systems have a limited servicelift, which may be based on usage or total work performed. An example ofsuch a component is the rope or cable used to lift loads. Over time thecable may stretch, weaken, or otherwise become compromised from normalwork and wear and tear. Knowing when such items are due for replacementor inspection is important to reliable operation of crane or winchsystems.

What is needed is a system for addressing the above and relatedconcerns.

SUMMARY OF THE INVENTION

The invention of the present disclosure, in one aspect thereof,comprises a system having a cable drum that receives a length of workingcable that is wound in and out from the drum in response to poweredrotation of the drum with an uppermost layer of working cable on thedrum forming a working surface. A torque sensor in mechanicalcommunication with the cable drum measures a torque applied to the cabledrum due to tension on the working cable from a load. A drum heightgauge is provided for measuring a height of the working surface of thecable on the cable drum. A processor receives the torque value from thetorque sensor and the height of the working surface from the drum heightgauge and computes a force applied to the length of working cable due tothe load based on the torque and height of the working surface.

In some embodiments, the torque sensor measures the torque applied to acomponent within a torque path interposing the cable drum and a powersource. The torque sensor may be a magnetic sensor. Some embodimentsinclude a display device affixed proximate an end of the drum, thedisplay device providing a numerical readout of the computed force onthe working cable.

The drum height gauge may comprise a cable packer and/or an anglesensor. The processor may be incorporated into a load moment indicator,display, and/or a drum rotation indicator.

Some embodiments further comprise an electronic memory associated withthe processor. The processor records into the memory a cumulative amountof work performed by the length of working cable. The work is defined insuch case by the product of the force applied and the distance the loadis moved by the length of working cable. The electronic memory maycontain a cumulative work limit associated with the length of workingcable and the processor provides an alarm to an operator when thecumulative amount of work performed by the length of working cablepasses a predetermined fraction of the cumulative work limit.

The invention of the present disclosure, in another aspect thereof,comprises a system having a powered cable drum that receives a workingcable strung onto a boom to lift a load on the boom and that is woundonto the drum such that the load is raised and lowered in response torotation of the drum. The system includes a torque sensor that ismechanically connected to the cable drum and that measures a torqueapplied to the cable drum due to tension on the working cable from aload suspended from the boom, and a gauge for measuring a cable heightof the cable relative to the cable drum. The system includes a processorthat receives the torque from the torque sensor and a cable height fromthe gauge and computes a force applied to the length of working cabledue to the load based on the torque and the cable height.

In some embodiments, the processor is in electrical communication with adrum rotation indicator. The processor may calculate an amount of workperformed by the working cable utilizing the computed force and rotationdata from the drum rotation indicator. The system may include anelectronic memory associated with the processor. The processor storesinto the memory a cumulative amount of work performed by the length ofworking cable. The electronic memory may contain a cumulative work limitassociated with the working cable. The processor compares the cumulativework against the work limit and provides a notification when thecumulative work exceeds a predetermined threshold relative to thecumulative work limit. The processor may comprise a part of a loadmoment indicator computer.

The invention of the present disclosure, in another aspect thereof,comprises a device including a crane having a boom that suspends a loadwith a working cable. A cable drum is proximate an opposite end of theboom from the load. The working cable is wound onto the drum such thatthe load is raised and lowered in response to rotation of the drum. Atorque sensor is in mechanical communication with the cable drum so asto determine an amount of torque applied to the cable drum through theworking cable. A cable height gauge determines the height of workingcable wound into the cable drum, and a processor utilizes the torque andthe cable height to determine a force applied to the working cable bythe load.

In some embodiments, the processor comprises a component of a loadmoment indicator computer. The processer may utilize data provided by adrum rotation indicator to compute and store into memory a quantity ofwork performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view of a crane having dual hoists.

FIG. 2 is a partial cut-away elevation view of a first embodiment of ahoist and cable packer assembly utilizing the human-machine interfacedevice of the present disclosure.

FIG. 3 is a partial cut-away elevation view of a second embodiment of ahoist and cable packer assembly utilizing the human-machine interfacedevice of the present disclosure.

FIG. 4 is a perspective view of the hoist and cable packer assembly ofFIGS. 2 and 3.

FIG. 5 is a perspective view of the human-machine interface device ofFIGS. 2 and 3.

FIG. 6 is a schematic diagram of the human-machine interface device ofFIGS. 1, 2, 3, and 5 and associated inputs and outputs.

FIG. 7 is a perspective view of another embodiment of a hoist assemblysuitable for use with various embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various crane designs may rely on a load moment indicator (LMI) systemthat derives the load on the crane hook while simultaneously displayingan allowable load value to the operator. This LMI, sometimes referred toas a rated capacity indicator (RCI), or rated capacity limiter (RCL),also displays the percentage of safe working load, the boom length, theboom angle, the swing angle, and the radius of the load from thecenterline of rotation of the boom. The LMI also provides visual andaudible warnings of overload, two-blocking, and other crane conditions.The LMI calculates and displays these values in real time, using valuesderived from multiple sensors on the crane, including boom hydraulicpressure sensors, boom angle sensors, boom length sensors, and swingrotation sensors.

Allowable load may be calculated from the boom length, boom angle, cranegeometric data, and a crane-OEM-provided duty chart. The duty chart is amap of the allowable load for possible positions and configurations ofthe crane.

Central to the calculation of the load is the load-moment calculation.In the load moment calculation, the load is determined by dividing theload moment by the distance of the load from the center-line-of-rotationof the crane boom. This distance is also called the load radius. The LMIdetermines load moment by using the vertical component of the force onthe boom cylinder along with other factors. Previously this verticalforce component was derived through knowledge of the boom position, thegeometry of the crane, and the pressure on the boom cylinder at aparticular time. The LMI stores each crane's particular geometry innonvolatile electronic memory.

Commonly, LMI calculations occur on a computer referred to as the “LMIcomputer”. The LMI computer is typically mounted on a boom of a crane orembedded in a display in the crane's cab and has various interface portsfor electrical and pressure sensor inputs.

The device and system of the present disclosure may be implemented on,or as a part of, a crane apparatus such as crane system 10 of FIG. 1,possibly replacement or supplementing all or part of the LMI. The cranesystem 10 may include a crane base 12, comprising frame 12A and turret12B. In some embodiments these components are a vehicle, and avehicle-mounted swivel mechanism, respectively.

A crane boom 14 may be hingedly mounted to turret 12B. The boom 14 maybe raised and lowered (translated vertically) via a boom hydrauliccylinder 16. A cable 18A is supported by boom hydraulic cylinder 16 foraffixing to a load 20 to be raised or lowered or otherwise moved. Thecable 18A may be a steel cable, a woven steel cable, or other type ofsynthetic rope (and may also be referred to simply as a “rope” althougha natural, traditional style rope would not normally be used in moderncrane or winch applications).

The cable 18A is spooled onto hoist and cable packer assembly 22A. Inone embodiment, an auxiliary cable 18B is also supported by boomcylinder 16. Auxiliary cable 18B is spooled onto auxiliary hoist andcable packer assembly 22B. Depending on the application, crane system 10may be used with or without auxiliary hoist and cable packer assembly22B.

The auxiliary cable 18B may be of the same or a different type thatcable 18A.

Referring now also to FIGS. 2-4, hoist and cable packer assembly 22A(which may be mounted to turret 12B) may include a housing assembly 24having a first side plate 26 and a second side plate 28. A motor 29,which may be hydraulic, electrical, internal combustion, or of anothertype, may be affixed to first side plate 26. In an embodiment whereinauxiliary hoist and cable packer assembly 22B is also used, auxiliaryhoist and cable packer assembly 22B may have the same elements as hoistand cable packer assembly 22A and may function in the same way.Consequently, common features retain the same element number.

A hoist 30 may be located between first side plate 26 and second sideplate 28. The hoist 30 may be driven by an electric motor 29 (or othertype of motor) for paying in and paying out cable 18 from a drum 31(e.g., for winding and unwinding cable from the drum 31 to raise andlower loads). The hoist 30 includes a cable drum 31, which may berotationally mounted in housing assembly 24. The cable drum 31 may beprovided with grooves on an outer surface thereof for receiving cable18. The cable drum 31 defines an interior compartment 32 on the insideof cable drum 31. In some embodiments, the interior compartment 32defines interiorly facing teeth, known as a ring gear (not shown), on aninside surface of cable drum 31. The ring gear interfaces with a drivetrain 33 for imparting movement to the cable drum 31.

The hoist drive train, designated generally 33, is located withininterior compartment 32 of cable drum 31. The hoist drive train 33 ofthe present example is a double reduction planetary drive train.However, other types of drive trains may also be used, includingcompound planetary, or single or triple reduction planetaries, or othertypes. In one embodiment, hoist drive train 33 includes input sun gear34, input planet gears and carrier 36, output sun gear 38, and outputplanet gears and carrier 40. Input sun gear 34 communicates with motor29 for receiving torque from motor 29. Input planet gears and carrier 36communicates with input sun gear 34 for receiving torque from input sungear 34 and for providing gear reduction. Output sun gear 38 is incommunication with input planet gears and carrier 36 for receivingtorque from input planet gears and carrier 36. Output planet gears andcarrier 40 is in communication with output sun gear 38 for receivingtorque from output sun gear 38, and for providing gear reduction, andfor communicating with the ring gear with internal teeth on insidesurface of cable drum 31. In some designs, the input planet gears andcarrier 36 also communicate with the ring gear. Output shaft 42 is incommunication with the output planet gears and carrier 40.

A torque sensor 50 may be provided for measuring torque within hoistdrive train 33 and/or cable drum 31. In one embodiment, torque sensor 50is an input sensor 52 (FIG. 2), which is located adjacent to input sungear 34. In another embodiment, torque sensor 50 is an output sensor 54(FIG. 3) located on output shaft 42. Torque sensor 50 may be based onstrain gauge, magnetic field fluctuation, or other technologies.

By providing a measurement of torque on a known component in the drivetrain 33, the torque applied to cable drum 31 can be ascertained (if notmeasured directly). Various torque sensors (including, for example,torque sensor 50 and torque sensor 52) may arranged and configured tomeasure torque at various points along what would be called the torquepath. Components mechanically interposing (directly or indirectly) thedrum 31 and the motor 29, and directly or indirectly experiencing torqueapplied by either or both of these components may be said to be in thetorque path. Measuring the torque at any point in the torque path canprovide the torque, for example, on the drum 31 if the relationshipsbetween the components are known, as they are in systems such as thoseof the present disclosure.

The cable 18 may spool onto cable drum 31 in multiple layers. Cablepackers have various designs to keep the cable 18 in close contact withthe bare cable drum 31 (also known as the called the first layer) as itrolls onto the drum or to keep the cable 18 in close contact withadditional layers that rest on the layer of cable 18 below.

In the present embodiment a cable packer arm assembly 60 is affixed tohousing assembly 24. The cable packer arm assembly 60 has a base member62 having a first end 64 and a second end 66. The base member 62 ofcable packer arm assembly 60 is rotationally mounted to cable packerassembly axle 68, which is affixed to first side plate 26 at a first endand is affixed to second side plate 28 at a second end. The cable packerarm assembly 60 further includes a first roller arm 70 and a secondroller arm 72 (FIG. 4). A roller 74 is affixed to the first roller arm70 and a second roller arm 72 of cable packer arm assembly 60.

A right spring 76 is located on cable packer assembly axle 68 incommunication with the first side plate 26 and with the first roller arm70. A left spring 78 is mounted on cable packer assembly axle 68 incommunication with the second roller arm 72 and second side plate 28.The left spring 76 and right spring 78 are provided for biasing roller74 against cable 18 that is wrapped around drum 31. A packer anglesensor 80 (FIGS. 2 and 3) may be positioned inside of base member 62 ofcable packer arm assembly 60 for measuring a position of cable packerarm assembly 60 in relation to the cable drum 31.

The human-machine interface device 100 (FIGS. 2-6) may be receivedwithin interior compartment 32 of cable drum 31 and pass partiallythrough second side plate 28 for external visibility. The human-machineinterface device 100 may engage output shaft 42. The device 100 mayinclude a housing 102 and a display 104. The display 104 may be a colorliquid crystal display (LCD) visible on housing 102 or on any otherlocation on or proximate to the hoist or winch.

The device 100 may include a drum direction and speed sensor 106 (FIG.6) for measuring rotation of cable drum 31. Drum direction and speedsensor 106 communicates with a computer 108. In one embodiment, thecomputer 108 is connected to an on-crane computer network interface suchas a CAN bus interface. In addition, computer 108 may be connected toanother like device on another hoist on the same crane via an on-cranecomputer network, wireless sensor network, or a dedicated communicationcable linking the two. Also, computer 108 may be connected to anotherlike device on another hoist on a different crane on the same worksitevia a wireless sensor network

As can be seen in FIG. 6, the computer 108 additionally receives datafrom torque sensors 50 (e.g., input sensor 52 or output sensor 54) forcalculating torque. The computer 108 may be a microprocessor with anassociated electronic memory. In some embodiments, the computer 108 maybe system-on-a-chip device incorporating volatile and nonvolatilememory, a processor, and various I/O ports, D/A converters, A/Dconverters, and the like for communicating with the various sensors. InFIG. 6, two separate systems 100 are shown, associated respectively withthe main hoist 122A and auxiliary hoist 122B. In various embodiments,the computer 108 is embedded with, or a component of, an LMI, a DRI, adisplay screen, or other piece of hardware. In other embodiments, thecomputer 108 may replace the LMI and/or DRI.

In addition to the cable packers, other implements may be utilized todetermine rope or cable height on a drum (which may be necessary forderiving force on the cable from measured torque, as described above).Referring now to FIG. 7, a perspective view of such an implement isshown. The device of 700 of FIG. 7 comprises a series of angle sensors712, 714 mounted to a swing arm 716. One end of the swing arm 716 may beattached in a stationary relationship with respect to the drum 29. Theangle sensors 712, 714 may be located opposite the stationary end andmay be may be solid state electronic sensors. The sensors 112, 114provide an electronic signal that is indicative of the angle at whichthe sensor lies relative to a baseline (e.g., the sensor may provide theangle relative to horizontal). As shown in FIG. 7, the first anglesensor 712 is located and configured to measure the angle of the cable18 relative to the center of the drum 22. The second angle sensor 714 islocated and configured to measure the angle of the cable 18 relative tothe location where it pulls away from, or exits from, the drum 22.

Also mounted to the swing arm 716 is a line guide 718. In the presentembodiment, the second sensor 714 is actually mounted to the line guide718. The line guide 718 also serves to ensure that the angle sensors712, 714 remain aligned with the cable 18 as it exits the drum 29. Theangles measured by the sensors 712, 714 can be utilized to determinecable height relative to the center of the drum 31, as described in U.S.Patent Application Publication No. 2012/02090226, incorporated herein byreference as if set out herein in its entirety.

Referring now primarily to FIG. 6, an in-cab display 112 is alsoprovided and may comprises a telematics interface. A wirelesscommunication system 114 may be provided. In one embodiment, wirelesscommunication system 114 is Bluetooth®. Other wireless communicationssystems may be used, such as IEEE 802.15.4, wireless sensor networks, orwireless mesh networks. Wireless communication system 114 allows forcommunication with equipment in a cab of turret 12B, with otherequipment on the crane or on other proximate cranes in a wireless sensornetwork (see, e.g., FIG. 7, discussed below), or with crane spotters,riggers, or slingers nearby the crane during a lift. In one embodiment,a crane slinger is continuously notified of the cranesafe-working-load-percentage via a wireless near-to-eye display moduleworn by the crane slinger. In another embodiment, wireless communicationsystem 114 or a serial communications cable facilitates an ability todownload hoist usage information to a hand-held or other computationdevice. Such information may be stored on data logger 116 that is incommunication with computer 108.

Human-machine interface device 100 includes a power supply forconnecting to a vehicle ignition system or other power supply. Thehuman-machine interface device 100 may also include an LCD, OLED, LED,or heads-up display, wireless sensor or wireless personal area networkfunctionality, non-volatile memory, electronic real time clock, hoistand ambient temperature sensors, a global positioning system (GPS)module, a cellular modem module, an RS-232 or RS-485 serialcommunication port, a Universal Serial Bus (USB) interface, alightning-proximity sensing module, and an integrated near-to-eyedisplay or equivalent interface. The device 100 provides informationsuch as crane load moment indication functionality and data logging.

The capacity indicator on display 104 and/or in-cab display 112 showsdata received from computer 108 in communication with computer networkinterfaces 110 or 114. Computer 108 receives data from cable packerangle sensor 80 or from multiple angle sensors as described in U.S.Patent Application Publication No. 2012/02090226, as well as from boomlength sensor 118 and boom angle sensor 120. Benefits of calculatingwire force using torque sensor 50 and cable packer angle sensor 80and/or or multiple angle sensors via the methods set forth in US patentapplication publication No. 2012/02090226 include elimination of a needfor a typical LMI computer box and removal of pressure transducers on acrane boom hydraulic cylinder 18, which results in simplification ofcrane hydraulics plumbing and simplification of crane wiring byeliminating, in some designs, multiple hydraulic and electrical wiringconnections. The result is a substantial improvement in reliability,decrease in crane manufacturing time, complexity, and labor cost, and adecrease in service requirements.

Computer 108 may additionally receive data from other types of sensorsincluding hoist vibration sensor 130, anti-two block sensor 132, hoistoil condition sensors 134, and a lightning proximity sensing module 136.Computer 108 may also communicate with cellular modem 138 and GPS module140.

As set forth above, crane 10 may be used with hoist and cable packerassembly 22A (FIG. 1) as part of main hoist system 122A alone or may beused in conjunction with additional hoist and cable packer assembly 22B(FIG. 1) as part of auxiliary hoist system 122B. In an embodimentwherein both main hoist system 122A and auxiliary hoist system 122B areused, wireless systems 114 and computer network interfaces 110 of therespective systems communicate with one another.

Hoist and crane usage data stored on data logger 116 and/or computer 108may provide instantaneous information related to hoist “health” andhoist overload detection for an operator. Because the human-machineinterface device 100 is hoist mounted, the system may easily bemonitored by preventive maintenance managers without requiring startingthe crane engine or entering the crane cab.

Torque data from torque sensors 50 is relayed to computer 108 and/ordata logger 116. In one embodiment, data logger 116 only records torqueinstances that are greater than a threshold percentage of a rated torquecapacity of a winch, e.g., 80% of the rated torque capacity. Systemevents such as power on, power off, clutch disengage, and clutch engagemay also be recorded. Data stored in computer 108 and/or data logger 116are useful to schedule crane maintenance. Cumulated winch and crane idletime statistics may be monitored by crane fleet managers, likelyresulting in less fuel used and less frequent preventive maintenance.

Device 100 of the present disclosure receives, calculates, or has storedthereon, e.g., in computer 108, crane geometry, an OEM duty chart, boomlength, boom angle and wire rope force. Device 100 then provides realtime data related to allowable crane capacity and current load.

Torque, being defined as a force about a rotation point at a givendistance, can be used to determine the amount of force causing saidtorque if the distance at which the force is applied is known. In thecontext of the present disclosure, torque applied to the cable drum 31(e.g., about its central axis of rotation) is known by direct orindirect measurement as described herein (e.g., by torque sensors 50,52, 54). Furthermore, a cable height gauge is provided by the cablepacker angle sensor 80 (or the angle measurement systems described inU.S. Patent Application Publication No. US 2012/02090226). Knowing cableheight and the size of the drum 31, the distance from the central axisof rotation of the force causing the torque is also known. The computer108 or a processor contained therein can then easily make thecalculation of the amount of force applied to the cable 18.Understanding that there can be some variation due to friction of thecable 18 winding over the end of the boom 14 the force applied to thecable 18 will closely match or be equivalent to the weight of the load20.

In addition to the foregoing, the computer 108 can continuously store inmemory, or the data logger 116, the amount of force applied to the cable18. The DRI 106 provides data regarding the length of cable 118 beingwound or unwound, and hence, the distance the load 20 is moved. Work maybe defined as force multiplied by distance. Having access to both forceand distance of the load 20, the work performed by the cable 18 can alsobe computed and/or stored.

The human machine interface 100 of the present disclosure facilitatescollection of data such as real time hoist status and maintenancevalues, including actual hoist usage time and hoist duty cycle data,such as: hoist load profile over a specified period of time, hoistcumulative weight lifted over a specified period of time, type of hoistoverload conditions, number of hoist overload instances, severity ofhoist overload instances, average load factor, maximum hoist speed,ambient air temperature, hoist oil temperature, hoist oil viscosity,hoist oil water content, hoist oil acidity, hoist oil additive content,hoist oil wear particle content, load counts, crane and hoist idle time,excessive crane and hoist idle time, and load totals. The device of thepresent disclosure may also provide a visual indication of hoist serviceor impending service via a display, such as a light bar or LEDindicator, and a color or monochrome computer display that may bemounted on the enclosure or elsewhere on the hoist or winch.

The computer 108 may have stored in memory a total amount of work forwhich a given cable 18 is rated. This may take into account fatigue ofthe cable 18 as it is pulled in a straight line or as is winds orunwinds over the boom 20 and/or drum 31. The computer 108 maycontinuously accumulate the total amount of work performed by the cable18 as distances and forces are measured for each load lift. When thetotal amount of worked performed is within a given threshold of therated work capacity of the cable 18, the computer 18 may provide awarning or an alarm (e.g., via in cab display 112 and/or display 104).Therefore an operator or an inspector will know when the cable 108 isdue for replacement or inspection. Through interaction with the computer108, the stored load parameters may be reset (e.g., when the cable 18 isreplaced).

Another use the system 100 of the present disclosure is in monitoringsynthetic or metal rope installation onto a hoist or winch in which aminimum tension must be maintained. During installation on someconfigurations, rope must be laid on the hoist drum under tension and atthe proper rotation speed. The system 100 provides an “installationmode” in which it oversees the torque and speed on the hoist to assistin maintaining or monitoring the specified rope tension, speed, or otherquality.

The system 100 may also be used as a control system for activities inwhich the attached hoist or winch is involved. In one embodiment, thesystem 100 is a part of a pile driving system. The device 100 senseschanges in hoist torque and tool height and can be used to preciselycontrol slack on the cable, which is or special import in suchapplications as pile driving.

The system 100 may be used in connection with one or more similardevices mounted on one or more secondary hoists or winches on the samecrane. These devices may be connected through wired or wireless systems,wherein the multiple devices work together to assemble correct LMI orusage information. One device may be used as the primary or mastergathering point for this LMI and usage information.

In various embodiments, the systems of the present disclosure eliminatethe need for measuring hydraulic boom cylinder pressure. Consequently,LMI system installation on cranes is faster and less expensive andrequires less electrical wiring and hydraulic hose routing, resulting inan easier to assembly and more maintenance-friendly system than knownsystems. The HMI system of the present disclosure may be used on hoistinfrastructures and can be used in rough terrain, all-terrain, offshore,lattice-crane, and tower-crane environments. It should also beunderstood that the systems of the present disclosure can be used inwinch applications in which loads are pulled, as well as in hoists whereloads are lifted.

It is to be understood that the terms “including”, “comprising”,“consisting” and grammatical variants thereof do not preclude theaddition of one or more components, features, steps, or integers orgroups thereof and that the terms are to be construed as specifyingcomponents, features, steps or integers.

If the specification or claims refer to “an additional” element, thatdoes not preclude there being more than one of the additional element.

It is to be understood that where the claims or specification refer to“a” or “an” element, such reference is not be construed that there isonly one of that element.

It is to be understood that where the specification states that acomponent, feature, structure, or characteristic “may”, “might”, “can”or “could” be included, that particular component, feature, structure,or characteristic is not required to be included.

Where applicable, although state diagrams, flow diagrams or both may beused to describe embodiments, the invention is not limited to thosediagrams or to the corresponding descriptions. For example, flow neednot move through each illustrated box or state, or in exactly the sameorder as illustrated and described.

Methods of the present invention may be implemented by performing orcompleting manually, automatically, or a combination thereof, selectedsteps or tasks.

The term “method” may refer to manners, means, techniques and proceduresfor accomplishing a given task including, but not limited to, thosemanners, means, techniques and procedures either known to, or readilydeveloped from known manners, means, techniques and procedures bypractitioners of the art to which the invention belongs.

The term “at least” followed by a number is used herein to denote thestart of a range beginning with that number (which may be a rangerhaving an upper limit or no upper limit, depending on the variable beingdefined). For example, “at least 1” means 1 or more than 1. The term “atmost” followed by a number is used herein to denote the end of a rangeending with that number (which may be a range having 1 or 0 as its lowerlimit, or a range having no lower limit, depending upon the variablebeing defined). For example, “at most 4” means 4 or less than 4, and “atmost 40%” means 40% or less than 40%. Terms of approximation (e.g.,“about”, “substantially”, “approximately”, etc.) should be interpretedaccording to their ordinary and customary meanings as used in theassociated art unless indicated otherwise. Absent a specific definitionand absent ordinary and customary usage in the associated art, suchterms should be interpreted to be ±10% of the base value.

When, in this document, a range is given as “(a first number) to (asecond number)” or “(a first number)-(a second number)”, this means arange whose lower limit is the first number and whose upper limit is thesecond number. For example, 25 to 100 should be interpreted to mean arange whose lower limit is 25 and whose upper limit is 100.Additionally, it should be noted that where a range is given, everypossible subrange or interval within that range is also specificallyintended unless the context indicates to the contrary. For example, ifthe specification indicates a range of 25 to 100 such range is alsointended to include subranges such as 26-100, 27-100, etc., 25-99,25-98, etc., as well as any other possible combination of lower andupper values within the stated range, e.g., 33-47, 60-97, 41-45, 28-96,etc. Note that integer range values have been used in this paragraph forpurposes of illustration only and decimal and fractional values (e.g.,46.7-91.3) should also be understood to be intended as possible subrangeendpoints unless specifically excluded.

It should be noted that where reference is made herein to a methodcomprising two or more defined steps, the defined steps can be carriedout in any order or simultaneously (except where context excludes thatpossibility), and the method can also include one or more other stepswhich are carried out before any of the defined steps, between two ofthe defined steps, or after all of the defined steps (except wherecontext excludes that possibility).

Further, it should be noted that terms of approximation (e.g., “about”,“substantially”, “approximately”, etc.) are to be interpreted accordingto their ordinary and customary meanings as used in the associated artunless indicated otherwise herein. Absent a specific definition withinthis disclosure, and absent ordinary and customary usage in theassociated art, such terms should be interpreted to be plus or minus 10%of the base value.

Thus, the present invention is well adapted to carry out the objects andattain the ends and advantages mentioned above as well as those inherenttherein. While the inventive device has been described and illustratedherein by reference to certain preferred embodiments in relation to thedrawings attached thereto, various changes and further modifications,apart from those shown or suggested herein, may be made therein by thoseof ordinary skill in the art, without departing from the spirit of theinventive concept the scope of which is to be determined by thefollowing claims.

What is claimed is:
 1. A system comprising: a cable drum that receives alength of working cable that is wound in and out from the drum inresponse to powered rotation of the drum with an uppermost layer ofworking cable on the drum forming a working surface; a torque sensor inmechanical communication with the cable drum that measures a torqueapplied to the cable drum due to tension on the working cable from aload; a drum height gauge for measuring a height of the working surfaceof the cable on the cable drum relative to the cable drum; a processorthat receives the torque from the torque sensor and the height of theworking surface from the drum height gauge and computes a force appliedto the length of working cable due to the load based on the torque andheight of the working surface.
 2. The system of claim 1, wherein thetorque sensor measures the torque applied to a component in a torquepath interposing the cable drum and a power source.
 3. The system ofclaim 1, wherein the torque sensor is a magnetic sensor.
 4. The systemof claim 1, further comprising a display device affixed proximate an endof the drum, the display device providing a numerical readout of thecomputed force on the working cable.
 5. The device of claim 1, whereinthe drum height gauge comprises a cable packer assembly with an anglesensor.
 6. The device of claim 1, wherein the processor is incorporatedinto a load moment indicator.
 7. The device of claim 1, wherein theprocessor is incorporated into a drum rotation indicator.
 8. The deviceof claim 1, further comprising: an electronic memory associated with theprocessor; wherein the processor records into the memory a cumulativeamount of work performed by the length of working cable, the work of thelength of working cable being defined by the product of the forceapplied and a distance the load is moved by the length of working cable.9. The device of claim 8, wherein the electronic memory contains acumulative work limit associated with the length of working cable andthe processor provides an alarm to an operator when the cumulativeamount of work performed by the length of working cable passes apredetermined fraction of the cumulative work limit.
 10. A systemcomprising: a powered cable drum that receives a working cable strungonto a boom to lift a load on the boom and that is wound onto the drumsuch that the load is raised and lowered in response to rotation of thedrum; a torque sensor that is mechanically connected to the cable drumand that measures a torque applied to the cable drum due to tension onthe working cable from a load suspended from the boom; a gauge formeasuring a cable height on the cable drum; a processor that receivesthe torque from the torque sensor and a cable depth from the gauge andcomputes a force applied to the length of working cable due to the loadbased on the torque and the cable depth.
 11. The system of claim 10,wherein the processor is in electrical communication with a drumrotation indicator.
 12. The device of claim 11, wherein the processorcalculates an amount of work performed by the working cable utilizingthe computed force and rotation data from the drum rotation indicator.13. The device of claim 12, further comprising an electronic memoryassociated with the processor and wherein the processor stores into thememory a cumulative amount of work performed by the length of workingcable.
 14. The device of claim 13, wherein the electronic memorycontains a cumulative work limit associated with the working cable andthe processor compares the cumulative work against the work limit andprovides a notification when the cumulative work exceeds a predeterminedthreshold relative to the cumulative work limit.
 15. The device of claim10, wherein the processor comprises a part of a load moment indicatorcomputer.
 16. A device comprising: a crane having a boom that suspends aload with a working cable; a cable drum proximate an opposite end of theboom from the load, the working cable being wound onto the drum suchthat the load is raised and lowered in response to rotation of the drum;a torque sensor in mechanical communication with the cable drum so as todetermine an amount of torque applied to the cable drum through theworking cable; a drum height gauge that determines the height of workingcable wound into the cable drum; a processor that utilizes the torqueand the cable height to determine a force applied to the working cableby the load.
 17. The system of claim 16, wherein the processor comprisesa component of a load moment indicator computer.
 18. The system of claim17, wherein the processer utilizes data provided by a drum rotationindicator to compute and store into memory a quantity of work performed.